My comments on each of the wireless providers offering services in Canada. U.S. or other international provider opinions? See the FAQ regarding this commonly-asked question.
Telus Mobility offers services in most provinces within Canada. Services include 800/1900 MHz CDMA and AMPS.
Bell Mobility offers services in about half of the provinces within Canada. Services include 1900 MHz CDMA and AMPS.
Rogers offers services in all provinces and some territories within Canada, including 800/1900 MHz tdMA, 850/1900 MHz GSM, and AMPS.
Fido (owned by Rogers) offers 1900 MHz GSM services in most major Canadian cities.
Aliant Mobility offers 800/1900 MHz CDMA and AMPS in the Maritime provinces.
Telus Mike is primarily for business users across Canada. Mike uses Motorola's 800 MHz iDEN system.
Cityfone is a reseller of Rogers' 1900 MHz GSM network. They use the same network as Rogers/Fido, but different phones and monthly packages.
SimPro is a reseller of Rogers' 1900 MHz GSM network. They use the same network as Rogers/Fido, but different phones and monthly packages.
Virgin Mobile is a reseller of Bell's CDMA service. They use the same network as Bell, but offer different phones and monthly packages targeted at youth.